I tend to avoid mink and neatsfoot oils. Yes, they soften. But they also tend to weaken leather over the (very, very) long term.

As someone who's very life has depended on good custom leather boots on wildfires in the west I only use beeswax oils. Obenauf's is my favorite. The heavy boot oil is liquid and penetrates well. The solid leather preservative is fantastic as well. Melts by hand warmth. Being beeswax it can be buffed to a shine. Use a hair dryer to get it to penetrate a bit better. All my leather gets this treatment from custom and high end boots to motorcycle jackets to belts and knife sheaths.